The present invention relates to a connection coupling or separating device for conduits or for detachable conduit connection for, in particular, pressure-conducting fluid conduits having first and second coupling parts, in which a closed fluid flow path is present in coupled state, furthermore radial conduit sections of a coupling connection conduit and of a coupling part have mouth cross sections which can be brought into coincidence and, in the course of the coupling process, a valve closure in each coupling part can be opened and the mouth cross sections of both the coupling connection conduit and the radial conduit section of the coupling part can be closed by displacement, which displacement at the same time brings about the valve closure of the first and second coupling parts.
Such separating devices or couplings with radial passage therein of the fluid from one coupling part into the other require only a slight coupling force despite the fact that the fluid is under pressure. Therefore, only the sealing friction and possibly the restoring force of, for instance, spring-loaded closure valves need be overcome.
Couplings of this kind are known, for instance, from Federal Republic of Germany Patent 28 52 617 and OS 39 01 652. Both prior publications are, however, problematic with respect to leakage losses. The coupling in accordance with Federal Republic of Germany OS 39 01 652 leaves the conduit sections of both coupling parts open after emergence of the one coupling part, so that the portion of fluid present therein which is closed off by valve from the corresponding fluid conduit can escape unimpeded. The coupling in accordance with Federal Republic of Germany Patent 28 52 617 is so constructed that the radial conduit sections of the coupling parts are, to be sure, pushed away; upon the coupling or uncoupling, however, the mouth cross sections of the connection conduit come into the region of the transverse joint so that a loss can occur here.
Other known couplings of this type have the disadvantage that the reduced volume, occurring upon the coupling, between nipple which acts as a piston and bore which acts as cylinder is forced into the fluid flow path. This means an increase of pressure in the system, particularly in the case of hydraulic fluids.